Speed regulator for high-frequency alternators



Sept. 21 1926. l v

M. LATOUR SVPEEID REGULATOR FOR HIGH FREQUENCY ALTERNATORS Filed July 25, 1923 Fig. Z

INVENTOR MARXUS LATOUR TTORNEY Patented Sept. 21, 1926.

UNITED STATES PATENT OFFICE.

RADIUS LATOUB, OF PARIS, FRANCE, ASSIGNOB TO LATOUE CORPORATION, OF JERSEY cm, NEW JERSEY, A COBYOBATION OF DELAWARE.

SPEED REGULATOR FOB HIGH-FREQUENCY ALTEBNATOBB.

Application filed July 88, 1928, Serial No. 858,189, and 1n France October 8, 1922.

This invention relates to an arrangement for regulatin alternator driven by In accordance with the invention,

the speed of a high frequency a direct current motor.

the exciting circuit of the motor or of the generator feeding the motor com resistance the value of whic rises in series a may be directly varied by the flowing of the high frequency current in this resistance or in one of its elements.

Fig. 2 is a schematic dia gram of another form of the present invent1on employing a resistance device, the resistance of which varies with its temperature.

Let us assume that a Tungar t pe tube is inserted in the exciting circuit 0 the direct current motor which drives a high frequency alternator, and that it is inserted in such a manner that the exciting current may flow from the plate of the Tungar to its filament.

The internal resistance of the Tung ar tube may now be easily varied by a hlgh frequency current enerated by the alternator,

if the filament is heated by this high frequency current.

Instead of the Tungar tube, a boron filament may be connecte in series with the exciting circuit. As well known, the resistance of boron varies considerably with the effective intensity of the current by which it is traversed. If this boron filament is traversed at the same time by a high frequenc current generated by the alternator then t e resistance which is in series with the exciting circuit will be noticeably modified dependn quency a ternating current.

The same thing will happen, opposite sense,

on the intensity of this high frebut in the if the exciting circuit is connected in series with metallic filaments (e. g.

tungsten or iron filaments).

In any case, circuit will be modified without ing any mechanical action by this quency current itself.

the resistance of the exciting rformigh fre- For the purpose of speed regulating, the hlgh frequency current may be shunted at the termlnals of the alternator through a circuit which is tuned either to a higher fre- 55 quency (Tungar tube, boron filament), or to a lower frequency (metallic filaments).

Th1s tuning system may of course be comblned with any other known tuning system, and the high frequency circuit which feeds co the variable resistance may be actuated by the output of the alternator.

The invention is applicable to-systems in which the high frequency current must mod1fy the resistance of the circuit of a magnetic amplifier or of an alternating current circuit in case the driving motor is an alternating current motor.

Referring to Fig. 1, a direct current motor '1 is connected across a direct current source of power as shown. Motor 1 is arranged to drive an alternating current generator 2 which in turn supplies an alter nating current loa'd. A tuned control circuit 3 comprises asecondary winding of the coupling transformer 4 and the filamentary cathode of a two element electron vacuum valve 5 connected as shown with the variable condenser 6 connected across the terminals of the secondary winding of trans- 0 former 4. The shunt field 7 of the direct current motor is connected across the direct current source of power through the electron valve as shown.

The system shown in Fig. 1 functions in as the following manner:

The alternating current generator 2 is arranged to deliver power: at a predetermined frequency. The tuned control circuit 3 is made sharply resonant to a frequency so slightly above that of the predetermined frequency. If the load supplied by the alternating current enerator is reduced, its frequency will ten to rise even though the motor 1 has a flat speed characteristic. This, of course, is due to the fact that the motor 1 must readjust itself to the new load condition.

When the frequency of the alternating current generator becomes equal to the reso-\ nant frequency of the tuned control circuit 3, a substantial increase ofcurrent will result in the filamentary cathode of the vacuum devicelb. The increased electron emission from the filamentary cathode Wlll .result in an increased flow of current through the shunt field winding 7 effecting a quick de-acceleration of the motor speed and a decrease in the frequency of the generator 2 back to the above mentioned predetermined value.

Now referring to Fig. 2, a direct current motor 10 is connected across a direct source of power shown and is arranged to dr ve an alternatin current generator 11 which 1n turn suppfies variable alternating current to a load.

A tuned control circuit 12 is inductively coupled across the output of the alternatin current generator by means of the coupling transformer 14. This tuned control circuit 12 comprises the secondary winding of the coupling transformer 14 and a filamentary resistance 16 having a positive or negative temperature coefficient such as boron or metallic filaments, respectively, arranged as shown with the variable condenser 17 connected across the terminals of the seconda winding of the coupling transformer 14. he tuned control circuit 12 is provided with a control switch 20 whereby this circuit may be disabled, if desired. The filamentary resistance 16 and a shunt field winding 22 of the direct current motor are connected in series across the direct current source of power as shown. The tuned control circuit is made sharply responsive to a frequency slightl above or slightly below the predetermine frequency of the alternating current generator 11, depending on the character of the resistance 16 employed.

If the load on the alternating current generator is now reduced, the speed of the motor will tend to increase, and when the frequency of the alternating current generator increases to a value equal to that to which the tuned control circuit 12 is resonant, a substantial increase of current will flow .through the filamentary resistance. If this resistance is of boron, the resistance of which decreases with heat, there will result an increased flow of current through the shunt field winding 22. This will quickly reduce the speed of the motor 10, resulting in a quick decrease of frequency of the alternatlng current generator to its predetermined value. If the filament of resistance 16 is of a material whose resistance increases with the temperature, the tuned circuit 12 is made sharply resonant to a frequency slightly below the predetermined frequency of the alternating current generator 11.

If now, for any reason, the frequency of the generator decreases owing to a reduction in speed of the motor 10 when the frequency decreases to a value equal to that to which the circuit 12 is resonant, a large increase of current will fiow in the resistance 16. This resistance will then increase in value resulting in a decrease of current flow through the shunt field winding 22. This will accelerate the speed of the motor to its desired value, resulting in an increase of the frequency to its predetermined value.

The-several modifications are merel illustrative of the present invention an are not to be taken as limiting the scope of the invention.

Having described my invention, what I claim is:

1. A high frequency current generating system comprising an alternator, a direct current motor for driving the same .comprising an excitin winding, a resistance in series with said winding, the value of which is a function of the current therein, and means for impressing on said resistance a current derived from the output circuit of said alternator.

2. A high frequenc current generating system comprising a igh frequency alternator, a direct current drivin motor therefor, having an exciting win ing, a boron filament in series with said winding, and means for impressing on said filament a current derived from the output of said alternator.

3. A high frequency current generating system comprising a high frequency alternator, a direct current driving motor therefor, said motor having an excitin windin and a resistance in series therewith, the va no of which is a function of the current therein, and means for supplying said re sistance with current derived from the output of said alternator, said means, comprising a tuned circuit coupled to the output circuit of said alternator.

4. In a high frequency current generating s stem comprising an alternator, a motor or driving said alternator, a control circuit for said motor, a resistance in series with said control circuit, the value of which is a function of the current therein, and means'for impressing on said resistance a current derived from the output circuit of said alternator.

5. In a high frequency current generating system comprising a high frequency alternator, a motor for driving said alternator, a control circuit for said motor, a boron resistance in series with said control circuit, and means for impressing on said resistance a current derived from the output of said alternator.

6. In a high frequency current generating rent therein, and means for supplying 'said resistance with current derived from the output of said alternator, said means comprising a tuned circuit coupled to the out- 5 put of said alternator.

7. In a high frequency current generating system comprising an alternator, a motor for driving said alternator, a control circuit for said motor, a heat controlled variable resistance in series with said control 10 circuit, and means for supplying current from the output of said alternator for va- 

